PETR 38 |
| The following topics related to methane gas hydrate behavior have been studied in the laboratory: effect of formation mechanisms, grain size effects on acoustic velocity, pore-pressure effects during formation and shear, and modeling the pore-scale location of interstitial hydrate. P-wave velocity (Vp) increases abruptly during initial hydrate formation in fine-grained sediment, but reaches values that are much lower than Vp obtained in Ottawa sand. Cementation is likely in the presence of substantial amounts of free gas, because hydrate forms at locations coated with water molecules, that is, on grain surfaces and at grain contacts. However, many natural samples are located in regions where free gas probably doesn't occur. As such, they do not appear to have grain cementation. Specimen grain size and laboratory hydrate-formation methods need to accurately represent the natural conditions being modeled. Otherwise, there can be important differences between naturally occurring and laboratory-formed hydrate. |
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Symposium on Gas Hydrates and Clathrates
1:00 PM-3:55 PM, Monday, 14 March 2005 Hyatt Regency -- Madeleine C-D, Oral
Division of Petroleum Chemistry |